"King Knut has much shrewdness," ejaculated Anund, "for he knows that I would fain win treasure, and that I know little of courtly custom. But King Olaf I have known since I was a boy, and learned to love him so much, that I cannot now forsake him." Possibly it was this staunch attitude of Anund Jacob which discouraged Knut from waging open war against Olaf. At all events he went (1026) as a pilgrim to Rome, not as conqueror to Norway. In the meanwhile, his brother-in-law, Earl Ulf,[A] headed a rebellion against him in Denmark, and entered into an alliance with Olaf Haroldsson and Anund Jacob. Both thought this a convenient opportunity for striking a blow at the threatening power of Knut, and gathered a fleet with which they ravaged the coasts of Halland and Skaane. They even in some places summoned the people to the _thing_ and received their homage. These tidings reached Knut who promptly returned from his pilgrimage, and came within a hair of capturing the two kings who did not suspect that he was near. Knut's ships were so greatly superior both in size, number, and equipment, that it would have been folly to remain and await battle. Olaf and Anund, therefore, hastened along the coast of Skaane toward Swedish territory, hotly pursued by Knut. They put up in the Helge-aa, a short river, uniting a series of lakes, near what was then the boundary between Sweden and Denmark. Olaf made haste to dam up the river where it issued from the lake, and filled the river-bed with a mass of trees and other obstructions. Late in the afternoon Knut sailed into the harbor, and found it deserted. The allies lay with their fleet outside the harbor, apparently ready for battle. It was, however, too late in the day to begin the fight, and Knut left part of his fleet outside to watch them. In the night the command was given to break the dam, and an enormous volume of water rushed down upon the Danish and English fleet, which broke from its moorings, and drifted seaward in disorder. A considerable number of people were drowned, but the ships though much damaged were not wrecked. The confusion was, on the whole, less than had been anticipated, and Earl Ulf, seeing that there was a chance that Knut might save himself, turned traitor once more and went to his rescue. The Swedes and the Norsemen, perceiving that the Danish king with this accession of strength was too formidable, sailed away without making an attack (1027). Knut, instead of pursuing them further, sailed back to England, but in the following year returned with a greatly increased force. He had by his extensive system of bribes effectually secured the friendship of the disaffected Norse chiefs, and therefore steered without hesitation to Nidaros where he was proclaimed king of Norway. He appointed his nephew Earl Haakon, the son of Earl Erik, regent in his absence.